Recording and indicating thermometer for stills.



R. DUNWDDY RECORDING AND INDIGATING THERMOMETER FOR STILLS.

APPLICATION FILED MAR. 11, 1911.

1,035,952. I v Patented Aug.20, 1912.

ROBSON DUNWOIDY, OF KIRKWOOD, GEORGIA. ASSIGNOR TO NEAL NAVAL STORESCOMPANY, A CORPORATION OF GEORGIA.

Specification of ,Letters Patent.

Patented Aug. 20, 1912.

Application filed March 11, 1911. Serial No. 613,933.

To aZZ whom it may concern:

Be it known that I, RoBsoN DUNWODY, a citizen of the United States,residing at Kirkwood, in the county of Dekalb and State of Georgia, haveinvented certain new and useful Improvements in Recording and IndicatingThermometers for Stills; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to indicating and recording thermometersespecially adapted for use in connection with the operation ofdistilling resinous gums, and has for its object to produce aninstrument of this nature which will be more reliable, and comparativelymore simple and less expensive to construct than those heretoforeproposed, and also one which, while constantly giving to the distillerthe temperature at all times inside the still, will keep a separate andprivate record not accessible to the distiller for the use of thesuperintendentor other person.

To these ends the invention consists in the novel details ofconstruction and combinations of parts more fully hereinafter disclosedand particularly pointed out in the claim.

Referring to the accompanying drawings forming a part of thisspecification in which like numerals designate like parts in all theviows:Figure 1 is a diagrammatic view in elevation of a still with myinvention applied thereto; Fig. 2 is an enlarged detail diagrammaticview partly broken away of the indicating and recording instrumentsoperated by my thermometer; and, Fig.3 is an enlarged sectional view ofa portion of the still with my thermometer in place.

1 indicates any suitable form of still, 2 the walls thereof, and 3 ahollow sleeve provided with a closed extension 4 fitted to said walls,projecting inside the still, as shown, thereby forming a closed pocketinto which the thermometer bulb 5 may be placed. The said extension 4 isinteriorly tapered, as shown, and the thermometer bulb 5 iscorrespondingly tapered in order that a close metallic fit may be hadbetween the said bulb and extension throughout the length of the bulb.

6 represents a flange rigid with the sleeve 3, and 7 a lock nutscrew-threaded on the portion 8 of said sleeve, and adapted to hold inconnection with the said lug 6 the sleeve 3 firmly in place. 9represents another lock nut screw-threaded upon the opposite end of thesleeve 3 and adapted to fit against the collar 10, fitting the tube orcasingll inclosing the asbestos or other heat insulating material 12,which surrounds the tube 3.

The thermometer bulb 5 is preferably made of metal such as steel and hasfitted thereto the metal pipe 13, which is also preferably of steel, andthe sleeve 14 is screwthreaded to said bulb as at- 15 and extends alongsaid pipe 13 substantially the length of the tube 3. Said sleeve '14 ispreferably flanged at its opposite end as at 16 and is.

fitted to the plug 17 through which the tube 13 passes, and over theplug 17 is fitted the adjusting nut 18, as shown. preferably screwthreads into the sleeve or casing 3 and abuts the flange 16 when theparts are in place. The said tube 13 is conveniently led a suitabledistance to the recording and indicating instruments, where it isprovided with the branch 20 leading to the indicating instrument 21, andalso is provided with the branch 22 leading to the recording instrument23. A. cock 24 controls the communication between the pipe 13 and thebranch pipes 20 and 22. The said indicating instrument 21 is suitablygraduated, as shown, and is provided with. a glass face 25 through whichthe indications of the temperature inside the still may be at all timesobserved by the distiller, but the recorded indications on the recordinginstrument 23 are hidden from view by means of the opaque covering 26,which may be locked in place by any suitable means, not shown. Thepurpose of preventing the distiller from seeing the records made uponthe instrument 23 is to afford a check on his operation of the still,and to enable his superior todetermine at the expiration of any giventime, whether or not the still has been properly operated. This is amatter of some importance in the distillation of turpentine, where thelabor employed is not always of the most reliable character.

Since the column of mercury divides'at 24 it requires that the mercurycolumn move twice the distance it would otherwise move if only a singlecolumn were employed. It, therefore, follows that any interference withThis nut 18 I in both instruments, thus doubly insuring I evidence ofimproper working in the still. It-

results from this, that it is of the utmost importance to have agoodconducting path across the joint between the casing 4 and the bulb, 5.It is also of the utmost importance that the bulb 5 be capable of aready withdrawal from the still and aready insertion into the still, inorder that when it is broken or otherwise out of order, a new instrumentcan be readily replaced or the old one repaired without interfering'withthe distilling operation.

Now, to secure a means of readily removing and replacing the thermometerin the still without disturbing the distilling operation, the extension4 1s provided, and this with the tube or casing 3 constitutes a closedpocketwhich enables the thermometer to be readily entered into the stilland taken from I the still without opening the same. And, in

order to secure a ready transference of heat from the still to themercury in the thermometer bulb, the closely fitting tapered surfaces onsaid bulb and extension are pro- 1 vided, which insure a metallic.contact throughout the length of said bulb and extension, and thereforeafford a minimum resistance to the passage of heat across the jointbetweeri the said parts. It' results, therefore, from this structurethat a pair of instruments such as 21 and 23 operated from the singletube 13 will be far more elficient when fed with mercury from a taperedbulb inclosed in a tapered extension than would be. the case were thebulb cylindrical, or were any other joints between the two partsadopted. Should the bulb be a cylindrical shape, then it is evident thatit might have a metallic contact with the extension only atone or twopoints, and thereby practically insulate the flow of heat into themercury. On the other hand, it is not practical to have the bulb exposedinside the still, not only on account of the still being open when thethermometer'is withdrawn, but also on ac count of the stirringinstruments employed in the still being liable to contact with the bulband'break the same. But by providing the adjusting nut 18 which isadapted to force the bulb 5 firmly into contact with the interior of theextension 4, I am enabled to get a joint between the parts-of a maximumconductivity.

In some cases it may be desirable .to coat the bulb 5 with. copper as bydipping the same into a copper sulfate solution or by.

other means, in order that a soft metal coat ing may be had between theinterior of the extension 4 and the exterior of said bulb, but I do notfind this precaution necessary when the adjusting nut 18 is employed.

course, when the bulb is coated with copper,

it is a comparatively simple matter to further coat it with mercury andthereby get possibly a still better contact, but I do not find thisprecaution necessary in practice.

When the still is equipped with instruments such as those abovedescribed, I find that it is thoroughly practicable to employ cheaplabor to operate the still, and for the reason that should the recordwhich is concealed from the operator show that he is not adding water tothe still at the proper times,

or has neglected his duty otherwlse, he can be at once held to accountfor his negligence and improved result-s secured at once.

This case differs from my co-pen'ding application filed March 8, 1911,Serial No. 613,073, and entitled thermometers,'1n that the saidapplication does not disclose the indicating and recording instrumentsas are disclosed herein.

It is obvious that those skilled in the art may vary the arrangement ofparts and the details of construction without departing from the spiritof my invention, and therefore I do not wish to be'limited to suchfeatures except as may be required by the claim.

What I claim is The combination with a still having an interiorlytapered pocket; of a thermometer having a bulb fitting in said pocket;means for forcing said bulb into tight metallic contact with saidpocket; an indicating and recording instrument; and a branchedconnection between said bulb and said indicating and recordinginstruments, substantially as described.

In testimony whereof, I aifix my signature, in presence of twowitnesses.

ROBSON DUNWODY.

'Oenieeot this patent may be obtained for he cents each, by addressingthe 'Waehlngton, D. 0.

Commissioner of Patents,

